Stress-distributed insulator



2 sheets-sheet l 1 INVENTOR ,fm j. J' 0xff/16100721@ BY 0m/M f'ffl ATTQR EY Feb. 27, 1923.

S. S. SONNEBORN STRESS DISTRIBUTED INSULATOR F1ld Apr. 24,

Feb. 27, 1923. 1,446,593

s. s. SONNEBORN STRESS DISTRIBUTED INSULATOR Filed Apr. 24, 1918 2 sheets-sheet 2 Patented Feb. 27, 1923.

UNITED sTATEs PATENT oFFlcE,

SOL S. SONNEBOBN, 0F BROOKLYN, NEW YORK, ASSIGNOB TO HOPEWEIJL INSULATION MFG. C0., A CORPORATION 0F lVIRGINIA.

' s'raEss-ps'rnrnu'mn INsUmfron Application tiled 511111.24, 1918. Serial No. 230,432.

To all whom 'it may concern.' i

Be it known that I, SoL S. SoNNEBoRN, a citizen of the United States, and a resident of Brooklyn, county of Kings, and State of New York, have invented certainnevsr and useful Improvements in Stress-Distributed Insulators, set forth in the following lspecification.

This invention relates to strain insulators, particularly of the high tension type and of the type sub'ected to considerable mechanlcal stress. he invention resides both in an 'individual strain insulator'unit and in part in a connected string of such units.

The broad object of my .invention isl to provide a strain insulator which wlll Withstand both electric and mechanical stress better than has heretofore been accomplished. A further object of my invention is to mm1- mize the size of a high tension strain insulator and the cost of its construction.

To the above ends it is one of my objects to distribute the electro-static' stress between the crossin contiguous parts of a strain 1nsulator which are subjected to wide differences of potential. It is also one of my objects to provide insulating material of a shape and character, between the parts subjected to severe mechanical stresses, whlch will best withstand such stresses and, in connection with this objective, I further pro pose to distribute the mechanical stresses to prevent a tendency for localized strain.

The above and further detail features of my invention will better be understood by reference to the illustrative embodiment described in the following specification in connection with the accompanying drawings, vwhich form a part hereof, in which like characters designate corresponding parts in the several vfigures and in which,-

Figure 1 is a vertical section through vone of my insulator units, with parts shown -in elevation and with its connection to a second unit of a string indicated; l

Figure 2. is a vertical section at right angles to the showing of Figure 1, taken through line II-II of Fig. 1,

Figure 3 is a detail plan of a stress-distributing plate; and y Figure 4 is a plan view of the insulator cross bars and stress-distributing saddle be` fore the same have been moulded into the im bedding insulating material.

In the drawings, A indicates an individual Outwardlyl extending insulator unit embodying myv invention be-v lng 1n this instance shown as the top unit of a string and connected with the second unit B of a string, which is identical with the unit A. At this stage of the description the peculiar symmetrical construction of my insu--n lator may be appreciated by noting that the insulator unit proper as shown in Figs. 1 and 2 has the identical appearance, in these Figures l and 2, provided that one of the figures is inverted and then compared with the other,

Each unit comprises a vairv of yokes C and D, which in this embodliment have their cross bars 1 and 2in interlinking relation. from the cross bar 1 in the yoke constructionjs'a pair of tension legs 3 and 4 and from the lcross bar 2 a similar pair of tension legs 5 and 6. Each cross bar preferably comprises a metal tube 7 threaded at the endsto have threaded engagement with the threaded eyes 8 of the tension legs and toreceive a lock nut 9. It is also preferably reinforced by an internal bar or pinlO, driven throu h the tubular bar 7, by which laminated or tion greatly increased mechanical stren h is imparted. Each tension leg prefera ly uilt-up construccomprises at its outer end an internally threaded nipple 11 having threaded engagement with the threaded outer end of each part 12 and providing a seat for the threaded end of an eye-bolt 13, the stem of which an?` chors one end of astress-distributing plate E, the central portion 14 of which is preferably flared into a disk-shaped formation from which the perforated lugs 15 extend.

Although the yokes C and D have been described as built up of a number of parts, which is the (preferred construction, it is to be understoo that the expression yokel is used in its broadest sense and doesnot exclude a construction in which a single bar is bent into U-shape. Although for some purposes, for example the reduction of heating from hysteresls, it may be preferable to construct t e yokes of non-magnetic metal such as brass, nevertheless, for purposes of great mechanical strength, it is considered preferably to have the cross bars constructed, both the tubular part and the reinforcing pin, of a high grade of steel.

Surrounding each cross bar 1 and 2 is a tube of insulating material. That for the bar 1 is indicated by the numeral 16 and is shown as a single tube preferably of compressed fiber Aot' the type capable of withstanding great mechanical pressure and having no tendency' to .soften upon heating. The insulating tube 17 for the cross bar 2 should be made of the same kind of insulating material. A preferable construction is shown built up of a plurality of tubular sections, which of course may be the construction tor thetube 16, it being desired .to conveyv the idea that either or both tubes may be ot'unitary or laminated'construction.

llnterposed between the insulating tube 16 and 17 is a saddle .lF of conductingmetal,

- preferably brass, which interposes a zone oit metal 18 between the insulating tubes 16 and 17 and lprovides transversely arranged channels 2O and21 .through which the tubes. 16 and 17 Ina pass to be embraced by the wings 22 tor t e'tube 16 and 23 for the tube 17. The space 2t between each pairoit wings 22 and 23 is preferably centrally enlarged to torni the .circular opening 25 directly above the crossing point for the vcross bars 1 and 2 so that the electro-static distributing ed'ect of the enlargement 14: ot each stress-distributor Emay be greater.

At this point it vshould be noted that electro-static stress between the bar 1 and' the bar 2 would lnormallybelocalized in a vsmall areal representing the shortest disytance between these two bars. As these two bars are circular and are arranged in planes at .right angles to each other, these localities- "ci" shortest distance apart would approximate points. However, such is not the case ih my insulator. r'llhe saddle of conducting material F interposed between the cross bars increases 'the electrostatic area between the l cross Vbars so that the same is 'substantially uniformlydistributed over an area which may be measured rather in inches. Each such area approximates the walls of the vcross channels through the saddle F. This saddle F, in addition to its service in distributing electro-static stress, likewise distributes mechanical stress over a very considerable area so that the necessary diameter for the insulating tubes 16 and 17- maybe greatly reduced and still ,successfully resist both puncture and crushing.- The metallic saddle F likewise serves as an eicient heat distributor to prevent local heatingof the insulation.V lt should likewise be noted that there is a Very considerable leakage surface distance between conducting parts of the two yokes. Y

, Each of the yokes is mechanically stayed in addition to the staying effected by the' saddle F in planes at right angles to each other by an imbedding body of insulating material 26, preferably electrose, whichhas` bosses 27 limbedding the o-uter ends of the yoke D and bosses 28 imbeddingthe"- outer intatte ends ofthe yoke C, and hips 29 enveloping the ends of the cross bar 1 and hips 30 enveloping the ends otl the cross bar 2. The central portion of the contour of this imbed-v vand 2, but the symmetry is such that the f construction on one side of the plane is rotated 903 from the construction on the op- Hposite sident said plane. i

'llhis imbedding body 26 of insulating material weatherproofs all the parts, and adds to the insulation between the yokes.

4ln connecting my insulator units such as A and B in a string, the eyes of the eyeloolts 13 cfa yoke C are each individually directly linked by a suitable Hexible 'connection lwith the eyes of the eye-bolts 13 of La yoke G of the next contiguous insulator. lsuitable connecting means is a C-link 31.

. By this method of'interlinkage a straight line pull is provided. between thetension legs of each interconnected yoke so that there is no tendency to bend a lpair of legs such as 3 and 4 together-at their outer ends.

However, the ends oitv a string 4of insul lators are preferably connected .with a support or the part to be supported through the medium of a straddling shackle 32 having eyes 33 to be connected each with an eye of eye-bolt 13 in any suitable .manner as bya C-l'ink31. D

Although I have" described a preferred embodiment of my invention in detail, it is to be understood that myl invention is by no means4 limited to the detailed construction described, but has the full-breadth and scope lof the following claims,vsome of which are not even limited to an interlinked relation of lthe yokes. l

What 'l claimand desire' tosecure vby United States Letters Patent is 1. A" strain insulator comprising two substantially U-shaped metallic tension j structures. each comprising a pair 'of tension legs and a cross-piece, said structures being rf'rounding each cross-piece; a stress-distrib- ;iltin'g metallic connecting saddle for each of said `cross-pieces comprising a block having V- right angularly positioned cross-channels to f lit-said tubular insulating means; and ra body of insulating material enveloping said tension structures and saddle. 2. An .insulator comprising two relatively separated crossing bars adapted to be subjected to widely diferent potentials; a tube of insulating material about each of said bars at the locality of crossing; and a saddle of conducting material having crossing channels, one for each said tube of insulating material, for distributing the stress be tween said bars. l

3. A strain insulator comprising a pair of yokes each having a pair of separated tension legs, said pairs extending in opposite directions and a. cross-bar connecting the inner ends of each pair of tension legs, each said cross-bar comprising a metal tube reinforced by an internally positioned metal pin; and insulating material interposed between said cross-bars.

4. A string of strain insulator units, each said unit comprising a pair of tension yokes, each having a pair of tension legs, said pairsI of legs extending in opposite directions in planes at right angles to each other; and a flexible connection directly connecting each said tension leg ot' each unit with the corresponding tension leg of the' contiguous unit, whereby a straight line pull from tension leg to tension leg is insured.

5. A high tension strain insulator cornprising a pair of interlinked yokes comprising cross bars and tension legs; a tube of insulating material `for each cross bar; and a metallic saddle interposing a body of metal between said tubes of insulating material and at least partially embracing the same.

6. A high tension strain insulator' comprising a pair of inter-linked yokes comprising cross bars and tension legs; a tube or' insulating material for each cross bar; a metallic saddle interposing a body of metal be tween said tubes of insulating material and at least partially embracing the same; and a metallic electro-static stress distributor bridged between the outer ends of said tension legs.

7. A strain insulator comprising a metallic bar threaded at its ends; a pair of tension legs having eyes having engagement respectively with the ends of said bar; a nipple for each tension leg having'threaded engagement therewith, and an eyebolt seated in each said nipple; and a body of insulating material for said structure. A

8. A strain insulator for high potential duty comprising a pair of metal yokes each having a pair of separated tension legs and a crosspiece connecting the inner ends of each said pair of tension legs; a metal connector located between the cross-piece of one yoke and the cross-pieceof the other yoke and serving mechanically to connect said cross-pieces and to distribute both electrical and mechanical strains therebetween; and a separate barrier of insulating material between each said cross-piece and said metal connector, Whereb the effect of series connected insulation 1s effected.

Apr. 18th, 1918.

SOL S. SONNEBORN. 

